Multi-omics analysis reveals intratumoral microbiota as modulators of the immune environment within thyroid cancer.

Background: Recent studies indicate that intratumoral microbiota play a crucial role in tumor development. While research on microbiota and thyroid cancer (TC) has primarily focused on gut microbiota, studies on intratumoral microbiota are limited. This study utilizes multi-omics analysis to investigate the effects and mechanisms of intratumoral microbiota on TC. Methods: We analyzed the microbial profile in the TC tumor microenvironment using data from published The Cancer Genome Atlas (TCGA) program. The impact of microbes on TC signaling pathways and the immune environment was examined through a combined analysis of the microbiome, transcriptome, and immune infiltration. Results: Significant differences in microbial diversity were observed between TC tumor tissue and adjacent non-tumor tissue. Specifically, there were notable differences in the relative abundance of 12 microbial species at the genus level. Additionally, there were marked differences in the infiltration scores of 11 immune cell species in the tumor microenvironment compared to adjacent tissues. Nine of these immune cell species were correlated with eight differentially expressed genes, and these genes were associated with differential bacterial abundance at the genus level. Conclusions: Our findings reveal that the diversity and relative abundance of intratumoral microbiota are associated with tumorigenesis in TC.